Answer:
400
Step-by-step explanation:
There are 400.
Assuming the number must be at least 10,000, then:
In a 5 digit palindrome, the first and last digits must be the same, and the second and fourth digits must be the same; and:
For the first and last digit there is a choice of 4 digits {2, 4, 6, 8};
For each of these there is a choice of 10 digits {0, 1, ..., 9} for the second and fourth digits;
For each of the above choices these is a choice of 10 digits {0, 1, ..., 9} for the third digit;
Making 4 x 10 x 10 = 400 possible even 5 digit palindromes.
